biodiversity

Greek philosopher Aristotle described earthworms as the ‘intestines of the earth’. (Photo credit: USDA, Flickr)

Sustainable agriculture means the production of food from plants or animals using different agricultural techniques that protect communities, the environment, and animal welfare. The extensive use of chemical pesticides and fertilizers to boost crop yields may have resulted in good yields and productivity, but it has caused the efficiency of the soil to deteriorate throughout the world day-by-day. This modern agricultural practice has caused a steep fall in the biodiversity (above and below the ground) associated with cropland ecosystems.

Everyone knows forests are home to a wealth of biodiversity, with the Amazon alone hosting a quarter of global biodiversity. It is also now well established that diversity in crop production increases a farmer’s resilience to environmental stresses and shocks – from extreme weather to pests.

In terms of ending poverty, food insecurity and environmental degradation, agroforestry was positioned today at CFS44 as playing a crucial role in helping many countries meet key national development objectives epitomised under the Sustainable Development Goals (SDGs).

The rice ecosystems are inhabited by more than 100 species of insects. Twenty of them can cause potential economic losses. With the change in the climatic factors and modern cultural practices adopted for production a drastic change has been caused in the pest scenario in the recent past. Besides stem borer, gall midge, brown plant hopper and green leafhopper which were the major problems in past, several other relatively minor pests such as leaf folder, armyworms, cut worms etc. have gained importance. In a study conducted by the International Rice Research Institute (IRRI), it was found that, on average, farmers lose 37% of their rice yield to pests and diseases, and that these losses can range between 24% and 41% depending on the production situation (http://irri.org). All the pests are generally kept under check by their natural enemies (parasitoids and predators) by feeding on them. The food web of their relationships prevents the explosion of their populations and keeps them under economic thresholds mimimising the pesticide use.

Friday May 22nd was 2015’s International Day for Biological Diversity. This year’s theme was ‘Biodiversity for Sustainable Development’ which reflected the importance of biodiversity in achieving the Sustainable Development Goals. Biodiversity is key in agriculture and it both promotes and is promoted by sustainable methods. Farmers rely on a range of different species for the success of their crops. This may include barrier or repellent crops to prevent pests from attacking their crop, nitrogen fixing bacteria in the soil for nutrient availability, pollinators to transfer pollen between plants, and natural enemies to keep pest populations under control without the need for chemicals.

This month’s Factsheet of the Month, ‘Conservation of natural enemies of pests of vegetables‘ provides information about the role that natural enemies can play and the importance of maintaining populations of natural enemies in the field. This factsheet was written by staff from the Plant Protection Service in Sri Lanka. It is also available in Tamil and Sinhala.

Here’s a taste of some of the latest stories about plant health, including the discovery of how pests develop resistance to biotech cotton, the intensification of the battle against coffee rust, and a biodiversity assessment of over 10,000 Ghanaian cocoa farms.

A recent study carried out in Costa Rica found that insectivorous birds such as the Yellow Warbler help to reduce infestations of the Coffee Berry Borer Beetle on coffee plantations by 50%. This free pest control service is estimated to save a medium sized coffee farm up to $9,400 per year. The study carried out by biologists from Stanford University could provide incentive for biodiversity conservation and enhancement of ecosystem services and also offer hope to coffee farmers devastated by the beetle.

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If you are active in the field of plant health or development and would like to contribute to the Plantwise Blog, please contact Donna Hutchinson. We are happy to post any credible articles that we think would be of interest to our readership.

Views expressed in contributions do not necessarily reflect official CABI or Plantwise positions.